With the development of broadband access technology, the operators are gradually accepting and deploying the Optical Access Network (OAN) to provide services with higher rate and higher quality to users. The PON technology is a point-to-multipoint optical access technology; FIG. 1 shows a schematic diagram illustrating network architecture of an existing PON; as shown in FIG. 1, the PON is composed of the OLT, the ONU and an Optical Distribution Network (ODN), wherein the ODN is of point-to-multipoint structure, and one OLT is connected with multiple ONUs through a splitter in the ODN.
With the progressive deployment and operation of the PON in the world, the number of the ONUs increases significantly with increase of the number of broadband users. At present, more and more requirements for power saving and emission reduction of the communication equipment are made. In 2009, power consumption of the single ONU operating in a full-load state is about 9 watts, and the specific value varies according to the implementation of the equipments of different manufactures. The value of power consumption has a certain room for further reduction with the increase of integrated level of the digital chip and the optimization of parts of optical components; at present, the European Union expects power consumption to be reduced by about 15% two years later.
Actually, power consumption of an optical module in the ONU is an important part of power consumption of the whole ONU equipment. In terms of actual use of users, there is usually no data stream generated when users surf the Internet, at this point, the optical module of the ONU is not needed; however, in the standard definition mechanism of the Ethernet PON (EPON), the optical module of the ONU keeps opening/closing to perform normal data communication with the OLT; as a result, the power is consumed in vain, and it is of no real benefit to the service for users, which goes against the requirement for power saving and emission reduction.